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Lean management systems: creating a culture of continuous quality improvement
  1. David M Clark1,
  2. Kate Silvester2,
  3. Simon Knowles3
  1. 1National Clinical Lead, NHS Improvement Diagnostics, Department of Histopathology, Path Links, Lincoln County Hospital, Lincoln, UK
  2. 2Health Sciences Research Institute, Warwick Medical School, The University of Warwick, Coventry, UK
  3. 3NHS Improvement, Southwest Pathology Service, Taunton, UK
  1. Correspondence to Dr David Clark, Department of Histopathology, Path Links, Lincoln County Hospital, Greetwell Road, Lincoln LN2 5QY, UK;


This is the first in a series of articles describing the application of Lean management systems to Laboratory Medicine. Lean is the term used to describe a principle-based continuous quality improvement (CQI) management system based on the Toyota production system (TPS) that has been evolving for over 70 years. Its origins go back much further and are heavily influenced by the work of W Edwards Deming and the scientific method that forms the basis of most quality management systems. Lean has two fundamental elements - a systematic approach to process improvement by removing waste in order to maximise value for the end-user of the service and a commitment to respect, challenge and develop the people who work within the service to create a culture of continuous improvement. Lean principles have been applied to a growing number of Healthcare systems throughout the world to improve the quality and cost-effectiveness of services for patients and a number of laboratories from all the pathology disciplines have used Lean to shorten turnaround times, improve quality (reduce errors) and improve productivity. Increasingly, models used to plan and implement large scale change in healthcare systems, including the National Health Service (NHS) change model, have evidence-based improvement methodologies (such as Lean CQI) as a core component. Consequently, a working knowledge of improvement methodology will be a core skill for Pathologists involved in leadership and management.

  • Management
  • Medical Education
  • Medical Informatics

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Lean is the term popularised by Womack and Jones1 ,2 to describe a management system derived from the Toyota Production System (TPS)3 that has been adapted and successfully applied to a wide variety of industries including healthcare.4 ,5

It is more than two decades since Don Berwick advocated continuous quality improvement (CQI) as an ideal in healthcare.6 A growing number of healthcare organisations throughout the world have employed management systems based on Lean/TPS to continuously improve their service to patients in an attempt to turn Berwick's vision into a practical reality. The healthcare organisations that have successfully implemented Lean management system were shown to deliver reductions in error rates and waiting times and increases in productivity.5 ,7 ,8 Moreover, Lean can deliver improvements in a relatively short timescale without the need for significant capital investment.1

Pathology services have long been at the vanguard of quality initiatives in healthcare, with much more established regulatory and accreditation frameworks than most other areas of medical practice, and unsurprisingly Lean management systems have been successfully applied to pathology services with similar gains to those seen in other industries.9–11 Lean is the basis for the CQI methodology used by NHS Improvement in its work with UK pathology services.12–14

It is important to emphasise from the outset that Lean is more than a set of management tools—it is a management philosophy with two key elements: data driven continuous improvement of processes focused on the needs of the end user and respect for the people delivering the service.2

In this article we will look at the origins and evolution of Lean, the theory and principles that underpin it and the ways Lean has been applied by healthcare organisations throughout the world to improve outcomes for patients and reduce the cost of healthcare. Later articles will describe how some of the key Lean tools can be used to improve processes in laboratory medicine with examples from pathology services that have successfully applied Lean, finishing with an exploration of the real difficulties managers and leaders have to overcome to implement and sustain a Lean management culture.

What is Lean?

When the TPS was studied by outsiders one of the most striking features was the absence of ‘fat’ (waste) in the system evidenced by very little work-in-progress (WIP) or inventory present between process steps. This required highly specified processes in which each process step sent a signal to the preceding step when it was ready to receive another piece of work (commonly known as just-in-time production). However, the most baffling thing to western managers was why, without large buffer stocks of WIP, the process did not repeatedly grind to a halt every time there was a problem. To understand how this is achieved requires an in-depth study of the values and principles that make up a Lean management system.

Lean is based on the principle that the purpose of any organisation is to create value for the people it serves (its users or customers). Value is created by satisfying a need or solving a problem for the customer (in the case of laboratory medicine, the customers are usually clinicians and patients). All value is delivered by processes—predictable sequences of actions that are linked together to deliver a desired outcome. Lean refers to the end-to-end process, extending from the customer request to the delivery of the service back to the customer. This is referred to as the ‘value stream’. Lean management systems focus on understanding what the customer needs and then redesigning and continuously improving the value stream by removing the waste that prevents value being delivered to service users. Waste is best defined as anything that consumes resources but does not contribute to creating value for the customer. Lean thinking subdivides waste into a number of categories (more about waste in later articles), but the most important type of waste to eliminate is error or defects that occur as a result of problems in the process.

In addition to waste, Lean identifies and targets two other signs of an unproductive process; the first is unevenness of workflow, which is often created by a poorly designed process in which capacity and demand are not matched at each step resulting in queues with excessive WIP; the second is overburden of staff or equipment by creating unreasonable expectations of what can be done at any point in time given the current state of the process. Lean is about helping people to work smarter not driving them to work harder.

Sustained improvements are the result of systematically analysing end-to-end processes to understand the root cause of the problems and taking actions to permanently address the underlying causes. Processes are redesigned to remove waste, smoothing the variation in demand at each step in the process and ensure that staff and equipment are not overburdened. Once this has been achieved, the process is standardised and each process step has its content, sequence, timing and outcome carefully specified. Clear visual management within the workplace is vital to achieve this degree of standardisation.

In a perfect process, work would flow seamlessly from one value-creating step to another, without waste, in response to customer demand. However, in the real world, such a perfect situation is unlikely to be achieved or maintained for any length of time, since customer demand and other factors, beyond the control of the management, are always changing and creating instability. Therefore, continuous improvement of processes with a commitment to fix problems without delay is an essential component of a sustainable Lean management system. Without it process performance will deteriorate and initial improvement will not be sustained. However, continuous improvement can only occur if the people who actually do the work are actively engaged and understand the principles that make up a Lean system.

This brings us to the two key behaviours that leaders and managers need to adopt in order to develop a sustainable Lean management system.15 The first is systematic data-driven problem solving using the scientific method (Plan, Do, Check, Act—PDCA see figure 1) to address the root causes of problems. We are all familiar with the PDCA cycle from audit, but too often audit is divorced from effective management action and follow-up, resulting in a failure to close the audit cycle loop. In Lean organisations, PDCA sits at the heart of all management functions from long-term strategy development16 to maintaining day-to-day activities in the workplace and without it progress cannot be sustained. The second key behaviour in a Lean management system is the fundamental role of managers at every level to go to the workplace and coach their staff in PDCA methodology in order to improve their problem-solving skills. The biggest challenge for a pathology department introducing a Lean management system is ensuring that everyone within the management team, including the clinical director, clinical leads and laboratory manager through to section heads, learn and routinely practice these two key behaviours17

Figure 1

(A,B) The Plan-Do-Check-Act (PDCA) Cycle. Access the article online to view this figure in colour.

The origins of lean

The origins of Lean predate Toyota and extend back more than 70 years. Many of the elements that form the basis of TPS and Lean can be found in the Training Within Industry (TWI) programme set up by the US Department of War in 1940 to provide consulting services to industries involved in the war effort.18

The programme trained over 1.6 million people over 5 years. TWI provided certified courses in what it called the three ‘J's’—Job Instruction (training), Job Methods (quality improvement), Job Relations (effective and fair supervision). TWI is credited with enabling the massive increase in production that underpinned the US war effort (figure 2). The methods allowed the rapid integration of untrained workers to replace skilled workers who had been drafted into military service. The TWI programme was introduced to the Japanese industry as part of the postwar reconstruction by the occupying military government led by General McArthur in the late 1940s. Ironically, just as Japanese industry was applying the TWI methods, the US industry was discarding them as skilled workers returned from war service to their original jobs. Many of the training methods and management practices that form part of Lean/TPS are little changed from those seen in the original 1940s’ TWI documents. W Edwards Deming who popularised the PDCA cycle (first described by Walter Shewhart) took his ideas and philosophy of quality management to Japan in 1947 at the invitation of the McArthur administration.19 A statistician by training, Deming applied a rigorous data-driven approach to quality improvement (using PDCA and statistical process control) and coupled this with a management philosophy based on a deep respect for the customer and the people who work within an organisation.20 Deming's philosophy of quality management was based on a number of key principles, the first and most important being that the key task of the leadership of any organisation is to ‘establish constancy of purpose’ towards continually improving the service to its customers. At this time, Toyota, a relatively small manufacturing company, was facing bankruptcy in the midst of a severe recession. Its very survival was at stake when Taichi Ohno led a transformation of fortunes by meticulously applying continuously repeating cycles of PDCA to all its processes and embedding this approach within TPS. Toyota continued to develop the TPS over the next three decades2 introducing many of the tools that form an important part of Lean. It is important to understand that TPS (and Lean) are management philosophies that, when applied properly, become an essential part of the culture of an organisation and hence outlast the tenure of individual managers and leaders.20 Box 1 summarises the 14 principles that underpin the Toyota way of managing.

Figure 2

A poster from WW II calling workers to meet the challenge of increasing production for the US war effort. Access the article online to view this figure in colour.

Box 1

The 14 principles that form the basis of the Toyota way (grouped into four sections).2


    • Principle 1—Base your management decisions on a long-term philosophy even at the expense of short-term goals


    • Principle 2—Create continuous process flow to bring problems to the surface

    • Principle 3—Use ‘pull’ systems to avoid overproduction

    • Principle 4—Level out workload

    • Principle 5—Build a culture of stopping to fix problems, to get quality right the first time

    • Principle 6—Standardised tasks are the foundation of continuous improvement and employee empowerment

    • Principle 7—Use visual control so no problems are hidden

    • Principle 8—Use only reliable, thoroughly tested technology that serves your people and process


    • Principle 9—Grow leaders who thoroughly understand the work, live the philosophy and teach it to others

    • Principle 10—Develop exceptional people and teams who follow your company's philosophy

    • Principle 11—Respect your extended network of partners and suppliers by challenging them and helping them improve


    • Principle 12—Go and see for yourself to thoroughly understand the situation.

    • Principle 13—Make decisions slowly by consensus, thoroughly considering all options, in order to implement decisions rapidly

    • Principle 14—Become a learning organisation through relentless reflection and continuous improvement (kaizen)

In the 1980s, the industry in the USA was being assailed by an influx of Japanese imports that were cheaper and were increasingly being recognised by consumers as being of higher quality and more reliable than the equivalent home grown product. Eventually this led to the realisation that the superior quality management systems embedded within the culture of many Japanese firms were one of the key reasons for their success. Deming, who by this time was in his 80s, was rediscovered by the US industry. His career underwent a renaissance and he was engaged as a consultant by several large US corporations, including Ford, Nashua and General Motors, to help redesign their management systems to focus on quality.19 Womack and Jones published their study of TPS and popularised ‘Lean’ as the term to describe this approach to management in the book ‘The Machine that Changed the World3 which sold over 400 000 copies and brought Lean management to a mass audience. The growing interest in the Japanese approach to quality management—and TPS in particular led some Western companies to engage consultants from Japan and apply Lean to their businesses, resulting in large improvements in the quality of their products and services, reductions in delivery times and increased productivity with little or no need for capital investment.1 This process accelerated as a number of large Western manufacturing companies (including Porche and the aeroengine maker Pratt and Whitney) seized upon Lean as a way of surviving the collapse in the markets for their products during the global recession of the early 1990s.

The organisations that have been most successful in developing and sustaining a Lean culture have understood and systematically applied its underpinning philosophy21 which was summarised by Fujio Cho, a former president of Toyota, in just six words ‘Go See, Ask Why, Show Respect’.

Application of lean to healthcare

Although Lean has its roots in the manufacturing industry, its philosophy and methodology are also applicable to service industries4 and elements of Lean were already being used in healthcare by the late 1980s. The application of a management system, originally developed by a Japanese car manufacturer, to medical care may at first seem to be contrary to the values that guide most healthcare professionals—after all, patients are not widgets, they are unique individuals, and need to be treated as such. However, as we have described above, the Lean philosophy of continuously seeking to improve service for the customer (patient), using repeated cycles of PDCA problem solving based on good evidence and data, coupled with respect for the people involved sits very comfortably alongside the values that most healthcare professionals espouse.

The adoption of Lean by healthcare organisations falls into three broad approaches.

The most successful approach (success being defined by sustained improvement) has been where a whole healthcare system or primary care or hospital organisation takes a high level executive decision to apply Lean to all its management processes. This is a massive undertaking, requiring long-term commitment to achieve large-scale cultural change. Lean thinking needs to be applied to redesign all patient pathways and the processes that support them and, like all transformational change, staff engagement is the key to success. Examples where this approach has been successful include the Theda healthcare in Wisconsin, USA,5 University of Michigan Medical centre,22 Flinders Medical Centre in Adelaide, Australia23 and Bolton NHS Foundation Trust.24 Organisations such as these have been able to demonstrate significant improvements in patient outcomes (fewer errors and reduced mortality rates), improved patient satisfaction and reductions in the cost of providing care as a result of freeing up capacity by removing waste. Organisations that are successful with this approach often take the Lean philosophy and methodology and then customise and rename it in order to build it into the fabric of the organisation and enable staff to identify with the new way of working. Pathology services implementing Lean in this environment can usually rely upon management support, with an infrastructure of support and training from elsewhere within the hospital.

A second, more common approach is to apply Lean thinking to a single service or care pathway within a healthcare system either as a result of an initiative led from within the service by the clinical leadership team (of which there are numerous examples in pathology) or as part of an external drive to improve a care pathway or service (eg, the work led by NHS improvement to reduce waiting times in cervical screening).13 Pathology services taking this approach require committed leadership from the clinical lead and managers within the department to successfully adopt and sustain Lean and will usually need to look outside their own hospital to find support and examples of how Lean has been successfully applied to similar services. A risk of this approach is that, although it may lead to significant improvement in some parts of the service for patients, this is not translated into improved outcomes if parts of the pathway are omitted from improvement. A key tenet of the work carried out by NHS Improvement in Pathology in the UK has been to emphasise that the end-to-end process starts and finishes with the patient. NHS Improvement provides a large number of online case studies, publications and tools to support pathology services engaged in improvement.25

A third approach, which unfortunately is not uncommon, is when senior management regard Lean as a management tool to remove waste (usually as a result of failing to understand and take on board the principles that lie at the heart of Lean). A department or service is identified as being ripe for the removal of waste and Lean tools are then deployed by experts from outside the department as part of a short-term improvement project. This approach may result in short-term improvement, but these often fall away because of failure to develop a Lean CQI culture.15 This approach can lead to a somewhat negative view of Lean, usually accompanied by the use of the term as a verb (to be ‘Leaned’) and a suspicion that the objective is to reduce staffing levels rather than improve quality. This approach is a misrepresentation of Lean.

Practical application of Lean to pathology

The application of Lean to laboratory medicine is growing as more pathology services throughout the world successfully use Lean to improve and design their services to meet patient demand. In the UK the most high profile example is the use of Lean to deliver improvements in the end-to-end pathway for cervical cytology13 resulting in the vast majority of cytology departments radically reducing turnaround times and eliminating backlogs.

In all the pathology disciplines the application of Lean has reduced turnaround times, reduced errors, increased productivity and improved space use, without the need for significant capital investment.10 ,11 ,14 ,25–27 In microbiology, Lean has been used to develop surge capacity to cope with sudden increases in demand.28 ,29

Dr Richard Zarbo, chairman of Pathology and Laboratory Medicine in the Henry Ford Health System, Detroit, has written a compelling and honest first-hand account of leading a Lean transformation in a large multisite hub-and-spoke pathology service over a 5 year period, and how by systematically applying the core principle of Lean and TPS he changed the management culture.17 Dr Zarbo started with a learning pilot in his surgical pathology laboratory before extending the approach to the other disciplines and hospitals within the group. The work was heavily influenced by a study of TPS by Steven Spear and H Kent Bowen who distilled the ‘DNA’ of the TPS to four simple rules (box 2). One of the key messages from the Henry Ford Health System experience is ‘It is all about leadership’ and they placed great emphasis on developing leaders who could understand and coach the Lean management philosophy by training 82 champions for Lean (out of a workforce of 785). This resulted in large reductions in process defects (55% in 1 year), improved turnaround times, space use (>800 sq ft reduction in the size of the automated core laboratory), and—very importantly—a big increase in staff engagement and job satisfaction (3.6 to 4.5 out of 5) measured using a standard Gallup employee engagement survey.11 ,17

Box 2

Four Rules of Toyota's DNA applied by the Henry Ford Health System17,30

  • Rule 1: Specify all work as to content, sequence, timing and outcome.

  • Rule 2: Every customer-supplier connection must be direct, and there must be an unambiguous yes-or-no way to send requests and receive responses.*

  • Rule 3: The pathway for each product or service must be simple and direct.

  • Rule 4: Any improvement must be made in accordance with the scientific method, under the guidance of a teacher, at the lowest possible level in the organisation.

*The term customer applies to internal as well as external customers—that is, each process step is the customer of the preceding step in the process.

Pathology services in the UK are facing their greatest challenges in a generation, as a result of the demographic and financial pressures confronting the NHS. These challenges are not unique to the UK. Lean offers a means by which leaders in pathology can rise to meet this challenge and deliver against the increasing expectations of our users, within the real resource constraints that face them. However, as we have described in this article, this is not an easy task or a quick fix. It requires a long-term commitment from the clinical and managerial leaders within laboratory medicine to create a new culture that delivers Don Berwick's vision of CQI as an ideal.

The next articles in this series will show in more detail how Lean can be applied to pathology and describe tools that can be used to map the end-to-end value stream, identify, quantify and remove waste and enable collaborative PDCA problem-solving and root-cause analysis. The final articles will discuss in greater detail the problems that need to be overcome when leading and managing the implementation of Lean in pathology in order to achieve a sustainable Lean continuous improvement management system.

Key messages

  • Continuous Quality Improvement (CQI) will be essential if pathology services are to meet the twin challenges of increasing quality and reducing costs.

  • CQI systems based on Lean principles combine systematic process improvement to improve the quality of service for users and patients and a commitment to value and develop the skills of the staff who deliver the service.

  • CQI cultures require leadership that is committed to practicing and coaching the Plan-Do-Check-Act cycle of improvement and embedding it in their management systems.

  • Go see, ask why, and respect people.


View Abstract


  • Contributors All the individuals listed as authors for the review article (Lean management systems: creating a culture of continuous quality improvement) have made a substantial contribution to the drafting of the article and have approved the final draft as submitted. No individuals who would qualify as authors have been omitted. DMC will act as guarantor for the article.

  • Competing interests None.

  • Provenance and peer review Not commissioned; internally peer reviewed.